UK Regulation (EU) No. 1321/2014, AMC2 Part 145.A.50(d), (AMC2) addresses conditions under which components can be removed from an aircraft and be issued with a CAA Form 1, provided that they are approved by an appropriately rated Part-145 aircraft maintenance organisation (AMO).
The Regulation places the responsibility to correctly identify and follow the requirements on the AMO issuing a Form 1. There is a potential for the AMO to use AMC2 in a way it was not intended.
The Civil Aviation Authority (CAA) policy is designed to address any possible misinterpretation by outlining the circumstance each paragraph in AMC2 is designed to address and explain the application of AMC2 when certifying aircraft components ready for release to service.
In accordance with Part-145.A.50(d), a certificate of release to service is issued by appropriately authorised staff at the completion of any maintenance on a component, whilst the component is off the aircraft. It is assumed that some maintenance would have been performed on the component to establish that it is in a serviceable condition and ready to be installed on a UK registered aircraft that falls within the scope of the UK Basic Regulation.
However, Part 145 provides for release of a used aircraft component to service, using a CAA Form 1 as the release document, without any substantive maintenance being performed. This is on the basis that conditions detailed in AMC2 to Part-145.A.50(d) have been satisfied, assuring the component’s serviceability.
The term ‘maintenance’ is defined in the Article 2 of the UK Regulation (EU) No. 1321/2014 as any one, or combination of overhaul, repair, inspection, replacement, modification or defect rectification of an aircraft or component, with the exception of the pre-flight inspection.
AMC2 refers to terms a ‘UK registered aircraft’ and a ‘serviceable aircraft’. These two concepts are not defined in the Regulation and therefore prone to be misconstrued, particularly when being considered in isolation. To help provide some clarity the two concepts are expanded on below, within the context of the UK Regulation (EU) No. 1321/2014.
Please note AMC2 only applies when using the privileges granted under a Part 145 A rating. It does not apply to privileges granted under a Part 145 B or C rating.
The concept of a UK registered aircraft
For the purpose of the AMC2, a UK registered aircraft is considered an aircraft which:
- has been registered in the UK, and
- the aircraft has gone through a process of establishing its conformity with the UK CAA system by means of having an UK Certificate of Airworthiness (CofA) issued by the CAA
Through the issuance of a CofA, the aircraft is certified as being in compliance with its Type Certificate which itself would have been either approved or validated by the CAA. A valid CofA therefore confirms aircraft compliance with UK CAA safety standards.
The concept of a serviceable aircraft
AMC2 para 2.6 refers to used aircraft components removed from a ’serviceable aircraft’.
When looking at serviceability of an aircraft, serviceability of its components must be assured. AMC2 2.6(b) states that ‘the aircraft component may only be deemed serviceable if the last flight operation with the component fitted revealed no faults on that component/related system’. A full compliance with subparagraph 2.6.1 is required for the component to be deemed serviceable.
A serviceable aircraft is one which has been admitted into the UK CAA system via a CofA, (M.A.904 applies for aircraft imported from a third country) and is in an airworthy condition (as per ICAO Airworthiness Manual doc 9760, meaning it conforms to its approved design and is in a condition for safe operation). A component removed from such an aircraft can be deemed serviceable and airworthy through the mechanism provided for in para 2.4 – 2.7.
The first determination in assessing applicability of AMC2 to used aircraft components is whether the aircraft from which the components have been removed is registered in the UK.
The second determination is linked to the airworthiness status of the aircraft and the issue of a UK CofA. If a valid CofA has been issued at the point of entry on to the UK aircraft register it means that the aircraft has been determined to conform with the applicable UK Regulations. Providing that the aircraft is maintained in a serviceable condition AMC2 para 2.6 can be applied. Serviceable used aircraft components can be removed and certified by an A-rated aircraft maintenance organisation (AMO) for aircraft within the scope of their approval.
It is possible for an aircraft to be on the UK register whilst its CofA has been surrendered or is no longer valid, for example when the Airworthiness Review Certificate (ARC) validating CofA has expired, or it has not been renewed or extended.
Given that such aircraft has held a valid UK CofA since entering the UK aircraft register, the requirement for aircraft to conform to a Civil Aviation Authority (CAA) approved/accepted type design would have been satisfied. In this case AMC2 2.7 applies where serviceable used aircraft components can be removed and certified by an A-rated aircraft maintenance organisation (AMO) with specific aircraft type approval.
The same principle applies in cases where a component is removed from a UK registered aircraft which, at the point of determination, has been removed from service though the aircraft has held a valid UK CofA. The aircraft would have conformed with the applicable UK Regulations and therefore serviceable used aircraft components can be removed and certified by an A-rated aircraft maintenance organisation (AMO) with specific aircraft type approval following AMC2 para 2.7.
However, if a UK registered aircraft has never held a valid UK CofA since entering the register, the aircraft’s airworthiness and safety standard would not have been assessed in accordance with UK regulations. Any component from such aircraft, although it can be removed by an A-rated aircraft maintenance organisation (AMO), it can only be certified by an appropriately rated B or C-rated AMO where the engine and components are specified within its approval, following AMC2 para 2.8.
In line with the first determination, any component removed from an aircraft that is not UK registered, AMC2 para 2.8 applies. An A-rated aircraft maintenance organisation (AMO) can remove the component though only a B or C-rated AMO where the engine and components are specified within its approval can release it to service.
Similarly, AMC2 para 2.8 is also applicable to any used aircraft component that is maintained by an organisation not approved in accordance with Part -145.
The Acceptable Means of Compliance (AMC) is clear that in the case of serviceable aircraft components removed from an aircraft that is not registered in the UK may only be issued with a Civil Aviation Authority (CAA) Form 1 if the component is leased or loaned from UK Part-145 approved AMO providing that the maintenance organisation retains control of the airworthiness status of the component. Such controlled component can then be loaned or leased with the intent to be installed on a UK registered aircraft. In this case, subparagraph 2.6.2 of the AMC applies.
Appropriately rated maintenance organisation
An organisation with an approval class rating for the type of component or for the product in which it may be installed.
Part-145 approved maintenance organisation
A maintenance organisation approved by the UK Civil Aviation Authority (CAA) under Part-145.
An aircraft which has been admitted into the UK system via a Certificate of Airworthiness and is in an airworthy condition, in other words, it conforms to its approved design and is in a condition for safe operation.
Serviceable aircraft component
A component that has been fitted to an aircraft which when it was last flown, no faults were revealed of the system within which the component operated.
The aircraft conforms to a type design approved under a type-certificate and any supplemental type-certificate, change or repair approved in accordance with UK Regulation (EU) No. 748/2012 (Part 21) and is in a condition for safe operation.
- Mandatory requirements for airworthiness (CAP 747)
- UK regulations (Basic Rule, Implementing Rules, AMC and GM material)
- UK Regulation (EU) No 1321/2014 and associated AMC & GM (the Continuing Airworthiness Regulation)
- Civil Aircraft Airworthiness Information and Procedures (CAAIPs) (CAP 562)
- The Air Navigation Order 2016 (ANO) and Regulations
- Aircraft Maintenance Incident Analysis - provides information on common causes where maintenance error has been a contributory factor in incidents and occurrences reported to the CAA
- The Confidential Human Factors Incident Reporting Programme (CHIRP) - Information Notice describing the services provided by CHIRP
- List of Approved Organisations
- The Part 145 holders guidance Certification of used aircraft components flowchart is provided to aid the correct determination of applicable provisions.